In order to study the effects of Jamyong-oil(蠶?油) on the diabetic rats induced by streptozotocin, during 15days rats were administered Jamyong-oil after streptozotocin injection(50mg/kg). On 2nd, 9th and 15th day, I investigated the levels of serum glucose, serum total cholesterol, serum triglyceride, serum amylase, and body weight. The last day, I killed rats and investigated hepatic lipid peroxide, tissue amylase. The results were obtained as follows: 1. Serum glucose levels of the sample group decreased effectively (p < 0.05) at the 15th day as compared with the control group. 2. Serum total cholesterol levels of the sample group decreased effectively (p < 0.05) at the 9th and 15th day as compared with the control group. 3. Serum triglyceride levels of the sample group decreased effectively (p < 0.05) at the 15th day as compared with the control group. 4. Activities of the serum amylase of the sample group increased respectively at the 9th (p < 0.05) and 15th (p < 0.01) day as compared with the control group. 5. Body weights of the sample group increased effectively (p < 0.05) at the 15th day as compared with the control group. 6. Hepatic lipid peroxide levels of the sample group decreased significantly (p < 0.01) as compared with the control group. 7. Tissue amylase levels of the sample group increased but not effective as compared with the control group.